This paper reports a prospective study of the incidence and magnitude of delays in the discharge of 80 elderly (65+ years old) patients admitted to two general medical services in teaching hospitals in Edmonton, Alberta. The average length of stay was 16.6 days. Discharges were delayed in 14% (11/80) patients, accounting for 21% of the total days stay. Patients whose discharge was delayed tended to be older, to have delirium and/or dementia, to more often come from or require transfer to long term care (LTC) institutions, and/or to be dependent in essential activities of daily living. The 4-Score, an index for predicting non-medical days, was useful in identifying patients at risk for delays in discharge, and had a sensitivity of 0.82, and a specificity of 0.90. Interventions to reduce delays in discharge must address the frail nature of the patients, their lack of support and existing administrative relationships with LTC institutions. Acute care hospitals will likely need to undertake formal programs for the long term care of many of these patients.